Agree the sample purpose first
Not every sample represents a finished production product. An early engineering pack may be intended to confirm the electrical concept, while a later sample verifies enclosure fit and manufacturing details. Ask the supplier to identify the stage and list any differences from the proposed production version. Record the sample serial or lot identification, drawing, cell selection, protection design and firmware revision. Without this baseline, a successful test can be difficult to reproduce when the next shipment arrives.
Test the real equipment duty cycle
A simple constant-current discharge gives useful information, but it may not represent the equipment load. Include startup, active operation, idle periods and the intended shutdown point. Record voltage and temperature throughout the sequence so the team can see how the system behaves near its limits. Use calibrated instruments and an agreed procedure carried out by competent personnel. The goal is to compare evidence against the specification, not to force a battery beyond its approved operating conditions.
Check fit, wiring and service access
Install the sample in the equipment using the planned mounting method. Inspect cable routing, strain relief, connector retention, polarity labeling and access for replacement. Check whether a cable can rub against a sharp edge or approach a hot component during normal use. Consider the assembly sequence as well as the final position. A pack that fits only when neighboring parts are removed may create production or maintenance problems. Feed these observations into the controlled drawing before final approval.
Review documents alongside the hardware
Request the proposed model specification, drawing, label artwork and relevant transport or compliance documentation. Check that the model identifiers and configuration match the sample. A report for a different cell or pack should not be treated as automatic coverage for the finished product. Ask the supplier to explain the scope and version of each document. Record any destination-market requirements with the product compliance team, and resolve missing information before committing to the planned shipment route.
Make approval specific and traceable
Use a short acceptance report listing the test method, equipment version, results, open issues and approved configuration. If a result differs from the requirement, agree whether the design changes or the requirement changes; do not leave the difference implicit. Keep an approved reference sample where appropriate and define how later substitutions will be communicated. For custom lithium-ion procurement, clear change control is as important as an attractive initial specification because a changed connector, cell or firmware can affect the assembled product. Share the final acceptance record with purchasing and receiving teams so the approved sample evidence follows the product into production.
Sources & further reading
Prepared for the lithium-ion battery packs collection. General engineering guidance does not replace a model-specific datasheet or application validation. Source review: 4 November 2026.